Talk toyour doctor about nexium. Independence day is upon us. Many relaxing and getting ready for the 4th of july here in milwaukee, old glory flapping in the background. As we begin this holiday, a popular vacation sport, parasailing is raising new safety concerns, two teenage girls were injured when their parasail crashed in florida. What went wrong and is this thrill too dangerous? Reporter: The video is difficult to watch -- two teens attached to a runaway parasail, catapulted into not one, but two condominiums, before slamming into a parking lot full of cars. Look again -- those strong florida winds causing the parasail to break loose from the boat. Tonight, the two 17-year-old girls from indiana, alexis fairchild and sidney goode, remain in critical condition. A similar incident played out in 2007 in pompano beach, florida, when the tow line attached to this parasail snapped, and as if they were slung from a gigantic slingshot, two sisters crashed into the roof of a waterside hotel, killing one and leaving the other with permanent brain damage. I don't believe it was an accident. I believe it was negligence. Reporter: Strong winds blew and the line snapped. Once that happened the parasailers are at the mercy of vicious gusts. The parasailing safety council estimates 130 million rides in this country in the last 30 years. Of those more than 400 have resulted in serious injury. 73 people have died. If parasailing is part of your upcoming vacation plans, look for a company that's been in buzz a long time. Major accidents will often put a company out of business. Monitor the weather. While responsible companies won't go out when the weather is bad or windy, some will. Keep an eye on the skies well before the parasail ever goes up. A good warning tonight.

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